Wound Dressing Materials

People are special. The importance and need for the research and development into medical and healthcare devices can never be overstated. In the 21st century, medical and healthcare devices play a more vital role in our lives than ever before. A wide range of materials are being used for producing numerous medical and healthcare devices for a variety of end use. In this manuscript, historical development of wound care dressings and products are reviewed. The characteristics and requirements of modern wound dressings are summarized. A core part is devoted to the description of the materials used in medical and healthcare devices. Selected synthetic polymers are listed with their applications in medical and healthcare devices. The advantages and limitations of fibres, metals, ceramics and composites are denoted. Textile structures are highlighted with their applications in medical and healthcare devices.

According to estimates by the National Audit Office (NAO) hospital acquired infections (HAI), in
particular surgical site infections (SSIs), cost the NHS on average £3200 per SSI and cause
a mortality rate of at least five thousand patients a year (Leaper 2010). Despite practitioners'
knowledge of safe working technique and control of infection, reported cases of nosocomial
infections are still high, despite a reduction in rate from 9% in 1993/4 to 8.2% in 2006 (Roberts
& Oookson 2009).

The current economic downturn in the UK and other countries has caused healthcare organisations to justify the costs of more advanced technologies. This is seen especially within the wound care discipline. The costs of healthcare account for a third of all UK government spend and with the prevalence of chronic wounds increasing, the cost of modern wound care is becoming more strained and open to scrutiny. Healthcare decision makers should not base their decisions on cost of dressings alone, but take into account the costs mitigated by using an advanced wound therapy. A clinical-economic assessment should be performed on a number of advanced therapies to assess if these are indeed more cost-effective long-term.

People are special. The importance and need for the research and development into medical and healthcare devices can never be overstated. In the 21st century, medical and healthcare devices play a more vital role in our lives than ever before. A wide range of materials are being used for producing numerous medical and healthcare devices for a variety of end use. In this manuscript, historical development of wound care dressings and products are reviewed. The characteristics and requirements of modern wound dressings are summarized. A core part is devoted to the description of the materials used in medical and healthcare devices. Selected synthetic polymers are listed with their applications in medical and healthcare devices. The advantages and limitations of fibres, metals, ceramics and composites are denoted. Textile structures are highlighted with their applications in medical and healthcare devices.

Electrospun poly(hydroxybutyrate) (PHB) fiber meshes have shown some success in wound dressing applications , however, their use is limited by their high hydrophobicity and brittle nature. In this study we investigated the effect of hydrophilization of electrospun PHB fibers by blending with Pluronic F-108 (PF) for use as a wound dressing material. Blending of PHB with different concentrations of PF (0.5%PF-PHB and 1.0% PF-PHB) before electrospinning led to a significant increase in the water wettability and swelling properties of fibers as compared to pristine PHB fibers. Further, it was observed that though the tensile moduli of PF blended PHB fibers were relatively lower as compared to PHB fibers, they show higher resistance to failure measured in terms of strain to failure and energy to failure. Moreover, PF blending significantly improved the in vitro blood clotting rate on PHB fibers when compared to control PHB fibers. Furthermore, the fabricated fiber systems were found to be cytocompatible and supported adhesion of fibroblasts in vitro. Finally, it was demonstrated that the PF blended fiber systems were suitable for the encapsulation of an antibiotic (doxycycline) to render them with antibacterial properties. Taken together, this study demonstrates that PF blending can be used to significantly improve properties of PHB fibers for wound dressing applications.

Aim: The wound is the consequence of an acute skin aggression either limited or spreading, sometimes iatrogenic, which may be worsened by a delay in care in peculiar circumstances. The aim of this study is to present the benefits and give potential indications of a waterproof dressing. This dressing guarantees the protection during the healing process and increases the patient’s compliance to the treatment of his wounds, even in difficult situations.
Methods: We used various dressings or means (primary adherent dressings, polyurethane film, cling film) to protect wounds in isolated or precarious care situations, but also in a more conventional context. Results: Secuderm® is the only dressing that is waterproof, reliable for acute and chronic protection for repeated exposures to water: excessive sweating, friction of clothing, projection or complete immersion under water. We report the use of Secuderm® in different exemption situations: in Guyana during French military missions by the Navy divers, in Cameroon for the treatment of Buruli ulcers, after arthroscopy, to protect medical devices (catheters, etc.) on acute wounds, or even during patient exposure to a nuclear, radiological, biological or chemical risk (NRBC). Discussion: To effectively protect a wound is difficult when the human resources and materials are limited. An efficient protection of the healing wound allows the resumption of professional, social and private activities in a certain comfort. Probably the only solution that is currently available, Secuderm® is a cunning waterproof protection for several days. Its indications are multiple whether in the treatment of acute, chronic or iatrogenic wounds, at the hospital, at home, in degraded situation or even when exposed to nuclear, radiological, biological or chemical risk. Prospective comparative studies are required.
But : La plaie est la conséquence d’une agression cutanée aiguë plus ou moins étendue, parfois iatrogène, pouvant être aggravée par un retard de prise en charge quand le contexte devient particulier. Le but de ce travail est de présenter les intérêts et les indications potentielles d’un pansement étanche. Ce pansement permet de garantir la protection du processus cicatriciel et d’augmenter l’adhésion du patient à ses soins, plus encore en situation difficile. Méthode : Nous avons utilisé divers pansements ou moyens (pansements primaire adhérents, film de polyuréthane, film alimentaire) pour protéger les plaies dans des situations de prises en charge isolées ou précaires, mais aussi dans un contexte plus conventionnel. Résultats : Le Secuderm® est une solution de protection étanche fiable en aigue et dans le temps lors d’expositions répétées à l’eau : transpiration importante, friction des vêtements, projection ou immersion complète sous l’eau. Nous rapportons l’utilisation du Secuderm® dans différentes situations d’exceptions : en Guyane chez des militaires en mission, des plongeurs de la marine nationale, au Cameroun dans le traitement de l’ulcère de Buruli, après arthroscopie, en protection de dispositifs médicaux (cathéters, etc.) sur des plaies aiguës, ou encore lors de l’exposition d’un patient à un risque nucléaire, radiologique, biologique ou chimique (NRBC).
Discussion : La protection efficace d’une plaie est d’autant plus difficile que les moyens humains et matériels sont limités. Une protection efficace d’une plaie autorise la poursuite d’une activité professionnelle, sociale et privée avec la garantie d’un certain confort. Probablement seule solution actuellement disponible, le Secuderm® assure une protection étanche astucieuse plusieurs jours. Ses indications sont multiples qu’il s’agisse des plaies aiguës, chroniques ou iatrogènes, à l’hôpital, à domicile, en situation dégradée voire même lors d’une exposition au risque NRBC. Des études prospectives comparatives sont nécessaires.

In this study, polyurethane (PU) film was prepared from palm kernel oil-based polyester (PKO-p) via prepolymerization with isocyanate/ polyol group ([NCO/OH]). PU films were physically characterized to investigate the
mechanical properties, thermal behavior, water uptake, water vapor transmission rates as well as biocompatibility and
antibacterial activities against Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli).
Results showed that PU 2 film exhibited optimum mechanical performance and thermal properties with the water vapor
transmission rates at 267 ± 17 g m-2 d-1, comparable to commercial dressing. Biocompatibility studies revealed that PU
films were non-cytotoxic to the human skin fibroblast cells (CRL2522) and exhibited bactericidal effect against both
bacteria

A series of poly(vinyl alcohol) (PVA)/poly(vinyl pyrrolidone) (PVP)/poly(ethylene glycol) (PEG) hybrid nanofibers were fabricated by an electrospinning method, in order to be used as a potential wound dressing material. The effect of Aloe vera was investigated in terms of solution properties such as viscosity, conductivity, pH and surface tension. The nanofibrous wound dressing materials were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC). SEM results revealed that the fiber diameters ranged between 200-500 nm and they were linear, homogenous and free of beads. DSC thermograms indicated that the addition of Aloe vera affects the crystal structure and efficiently cross-links the hybrid polymer, forming an amorphous structure with a melting temperature (Tm) of 219oC at an Aloe vera concentration of 3%. FTIR results clearly resolved the hybrid polymer structure of nanofibers obtained.

In this study, potential of the alginate based electrospun nanofibrous mats as wound dressings was investigated macroscopically in vivo experiments. 2/1 (v/v) %9 PVA / %1 NaAlg nanofibrous mats were produced by electrospinning method. In order to improve water resistance of the electrospun mats, the cross-linking was performed. SEM analyses, thickness and air permeability tests were applied for the nanofibrous mats produced as wound dressing and Suprasorb-A commercial alginate wound dressing. In vivo experiments, the healing performances of the wounds dressed by using cotton gauze, Bactigras, Suprasorb-A and the electrospun PVA/NaAlg nanofibrous mat were macroscopically evaluated and compared. The wound healing potential of the electrospun mat was better than that of cotton gauze including a drug and looked like antibacterial Bactigras. The results indicated that the electrospun PVA/NaAlg nanofibrous mat as wound dressing provided a good means for wound healing. ÖZET Bu çalışmada, elektro çekim yöntemi ile elde edilen alginat nanolifli yüzeylerin yara örtüsü olarak kullanım potansiyeli, gerçekleştirilen in vivo çalışmalarla makroskobik olarak değerlendirilmiştir. 2/1 hacimsel karışım oranında %9 PVA / %1 NaAlg çözeltisinden elektro çekim yöntemi ile nanolifli yüzeyler üretilmiştir. Bu yüzeylerin suya dayanımını geliştirmek için, çapraz bağlama işlemi uygulanmıştır. Yara örtüsü olarak üretilen nanolifli yüzeylere ve ticari alginatlı yara örtüsü olan Suprasorb-A'ya SEM analizleri, kalınlık ve hava geçirgenliği testleri uygulanmıştır. In vivo çalışmalarda, gazlı bez, Bactigras, Suprasorb-A ve elektro çekim ile üretilen PVA/NaAlg nanolifli yüzey ile kapatılmış yaraların yara iyileştirme performansları makroskobik olarak değerlendirilmiş ve kıyaslanmıştır. Elektro çekim yöntemi ile üretilmiş yüzeyin yara iyileştirme potansiyeli; ilaç emdirilmiş gazlı bezden daha iyi, antibakteriyel bir örtü olan Bactigras ile benzer olmuştur. Sonuçlar, PVA/NaAlg nanolifli yüzeylerin yara örtüsü olarak kullanılabilir olduğu öngörüsünü doğrulamıştır.

Interpenetrating network (IPN) of κ-carrageenan and poly(acrylic acid) was fabricated. Polyacrylic acid was synthesized as well as crosslinked in the presence of κ-carrageenan followed by crosslinking the κ-carrageenan in the presence of sodium ion. In order to fabricate glycidyl trimethyl ammonium chloride(Quat 188) modified κ-carrageenan IPN, κ-carrageenan was first coupled with Quat 188 in the presence of base followed by the fabrication of IPN. Analysis of the DSC thermogram revealed that the rigidity of the IPN improved with the increment of the κ-carrageenan content. Modification of κ-carrageenan further increased the rigidity. The IPNs swelled almost 300% in aqueous medium to form the hydrogels. Swelling was more pronounced in basic pH than in acidic pH. These hydrogels could incorporate approximately 94% of the prototype drug AgNO3 in 30min from aqueous medium.

Dressings are a real challenge in the care of patients with thermal burns. Th ey help to heal and prevent or treat possible skin infections. Paramedical teams must have a perfect strategy for organizing, managing pain and optimizing hygiene and asepsis rules. Th e purpose is to facilitate the understanding and implementation of this treatment by suggesting protocols that can be applied by all. It remains essential to mobilize specialized services to promote the evolution of burns.
Les pansements constituent un réel enjeu du parcours de soins des patients atteints
de brûlures thermiques. Ils participent à la cicatrisation et préviennent, ou traitent, les éventuelles infections cutanées. Les équipes soignantes doivent avoir une parfaite stratégie d’organisation, de prise en charge de la douleur et optimiser les règles d’hygiène et d’asepsie. L’objectif est de faciliter la compréhension et la réalisation de ce soin en proposant des protocoles applicables par tous. Il reste indispensable de mobiliser les services spécialisés pour favoriser l’évolution des brûlures.

With the recognition of health-related quality of life (HRQL) as an important and relevant outcome in pressure ulceration, it is important to gain better understanding of the complex relationship among the various factors that affect it. A problem with existing literature in this area is that the impact of having a pressure ulcer on HRQL is combined conceptually with contributory factors which may influence outcome. This study identified contributory factors affecting pressure ulcer-related HRQL and explored interrelationships between factors based on views of adults with pressure ulcers. We obtained patient-reported qualitative data through semi-structured interviews with 30 patients with pressure ulcers recruited from hospital and community settings around England and Northern Ireland. Patients described how pressure ulcers affected their lives by recounting specific relevant events. Events (patient-reported issues) were sorted into categories and data framework analysed to produce a taxonomy of contributory factors. Inter-rater reliability established the extent of agreement between two independent raters. We identified 16 contributory factors, into two theme taxonomy: experience-of-care and individual-patient factors, defined by descriptive components. Our taxonomy is a comprehensive theoretical model of factors that contribute to pressure ulcer-related HRQL. We have also identified further research priorities to inform clinical practice.

Poly(vinyl alcohol)/sodium alginate nanofibrous mats were produced by electrospinning method at optimum process parameters. Evaluation of alginate-based electrospun nanofibrous mats as a wound dressing material and their comparison to commercially available wound dressings produced with conventional methods were carried out in vivo. Tissue specimens were examined histopathologically on 4th, 6th, 15th, 21st postoperative days. In contrast to other dressings it was observed that nanofibrous mat could survive on the wound crust in early stages of healing. In terms of epithelization, epidermis characteristics, vascularization and formation of hair follicles, nanofibrous mat showed the best healing performance. This could be explained with presence of nanofibrous mat acting as an artificial skin on the wound region until new tissue regenerated.

A recent study in the UK sought to identify practitioners' views on pain and trauma, and their relationship with wound care products. This important study involved a large sample of nurses from two national wound care organisations, and was the first serious attempt to understand this issue on a wider scale. Findings from this research prompted a broader investigation into the similarities and differences in Europe and North America. This article discusses the results of an international collaboration that sought to explore these issues further.

Didymosphenia geminata is a species of freshwater diatom that is known as invasive and is propagating quickly around the world. While invasive species are generally considered a nuisance, this paper attempts to find useful applications for D. geminata in the biomedical field and wastewater remediation. Here, we highlight the polysaccharide-based stalks of D. geminata that enable versatile potential applications and uses as a biopolymer, in drug delivery and wound healing, and as biocompatible scaffolding in cell adhesion and proliferation. Furthermore, this review focuses on how the polysaccharide nature of stalks and their metal-adsorption capacity allows them to have excellent wastewater remediation potential. This work also aims to assess the economic impact of D. geminata, as an invasive species, on its immediate environment. Potential government measures and legislation are recommended to prevent the spread of D. geminata, emphasizing the importance of education and collaboration between stakeholders.

To report the use and describe the interest of hemostatic dressings in a civilian setting, we provided medical prehospital teams with QuikClot Combat Gauze (QCG) and asked physicians to complete a specific questionnaire after each use. Thirty uses were prospectively reported. The wounds were mostly caused by cold steel (n=15) and were primarily cervicocephalic (n=16), with 19/30 active arterial bleedings. For 26/30 uses, hemostatic dressing was justified by the inefficiency of other hemostasis techniques. Those 30 applications were associated with 22 complete cessations of bleeding, six decreases of bleeding, and ineffectiveness in two cases. The application of QCG permitted the removal of an effective tourniquet that was applied initially for three patients. No side-effects were reported. The provision of hemostatic dressings in civilian resuscitation ambulances was useful by providing an additional tool to limit bleeding while rapidly transporting the injured patient to a surgical facility.

The authors Varela et al. (2020) pose interesting, relevant questions related to silver-containing wound dressing toxicity, antimicrobial effects, effect on the transition from the M1 to the M2 macrophage phenotypes, and effect on wound inflammation overall. They designed creative studies to answer these questions using six primary dressings: Atrauman, Biatain, and PolyMem WIC, all with and without silver. Four bacterial strains known to infect open wounds (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa), and three human cell types (fibroblasts, keratinocytes, and macrophages) were cultured. Test dressing discs were placed over two-dimensional bacteria and cell culture colonies, which were then incubated. Wells with test dressings covered with 2 mls of a bacterial broth were also incubated. The descriptions of wound healing, materials used, tests, and rationale are clear.

However, the study results are unlikely to be clinically meaningful because of two major design flaws:
(1) Contrary to the Instructions for Use, the researchers did not provide secondary (cover) dressings to prevent desiccation with any of the six study dressings, and
(2) The in vitro techniques used did not capture the multifunctional interactive attributes of polymeric membrane dressings (PMDs) such as PolyMem WIC and PolyMem WIC Silver, rending the results for these dressings clinically irrelevant.

Novel findings on fabrication techniques for bioactive materials, discovering further basic knowledge
about wound healing process, and availability of stem cells as alternative candidate for differentiated cells
have highly encouraged scientists for developing new bioengineered skin substitutes (BSS) that offer an
effective remedy for a specific wound type. However, technical, clinical, legislative and economic reasons
hamper wide-spread commercialization and clinical translation of BSS. Among the various types of
strategies that target skin repair and regeneration, tissue engineering with stem cells is most promising
route. Tissue engineering by cooperation of several disciplines forms a context on which the commercial
development of BSS is possible to provide benefits for patients who currently have limited or no cure
options. The principles of tissue engineering are to initiate cell cultures in vitro, grow them in monolayer
or on porous scaffolds and transplant the composite into a patient with a specific wound indication in vivo.
The potential for creating of custom-designed biomaterials and availability of stem cells from either
autologous or allogenic sources have helped to produce novel innovative BSS. Currently, wide range of
skin substitutes are already being fabricated for clinical use in different wound indications but not yet
definitively established. Therefore, many novel engineered constructs might be fabricated in the future.
In this review, we describe the progress that has been made to date in the field of skin substitutes and the
critical issues that are still hindering successful production and bench to bedside translation of BSS and
restricting the availability of these innovative therapeutic constructs. Integrity of the science and
technology, interdisciplinary expertise collaborations, and early interaction with regulatory entities such
as Food and Drug Administration (FDA) and European Medicines Agency (EMA), together with other
critical determinants, is vital to the successful commercialization of tissue engineering products into the
marketplace/clinic.